rsync processes hang and client failing on "max connections"

[Diburim]

rsync processes hang and client failing on "max connections",
I can't kill rsync process.

The temporary work around are:
increase max connections in /etc/rsyncd.conf
or
reboot the server !

The client get this error:
@ERROR: max connections (6) reached - try again later

$ ps -aux | grep rsync
admin    30408  0.0  0.0  1696  232 ?        S    Mar26   0:00 [rsync]
admin    28121  0.0  0.0  1688   40 ?        S    Mar26   0:00 [rsync]
admin    29137  0.0  0.0  1724   40 ?        S    Mar26   0:00 [rsync]
admin    30430  0.0  0.0  1724   40 ?        S    Mar26   0:00 [rsync]
admin    11476  0.0  0.0  1688   40 ?        S    Mar27   0:01 [rsync]
root      4529  0.0  0.6  2412 1704 ?        S    Apr10   0:03
rsyncd --daemon
admin    16211  0.0  0.2  1368  520 pts/0    S    02:48   0:00 grep rsync

Some rsync process never exit they are up for ~20 days.
I can't kill them, nothing happen when I try to:
kill 4529
kill 30408
etc...

rsync is started from inetd
rsync  version on the server 2.5.2 clients are 2.5.2 and 2.5.4

Please advise

Dib Urim